Mask ventilation assist device



FIG. 1 is a top view of a mask ventilation assist device, showing my new design;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1; and,

FIG. 3 is an enlarged view of the portion encircled in FIG. 2. 

CLAIM The ornamental design for a mask ventilation assist device, as shown and described. 